Compositions and processes for soaking silk and textile materials



Patented Mar. '2, 193

$ATEE? FWQE CQWQSK'EHQNS AND PRQCESSES FQR SOAK= ENG SEE AND TEX'EELE MATERKALS Dale S. Ghamberlin, Bethlehem, Pa, assignor to Warwick Chemical (10., West Warwick, R. 1., a corporation of Rhode island No Drawing. Application February 14, 1936, Serial No. 63,863

16 Claims.

The present invention relates to a process and material for treating yarns and it particularly relates to a process and product for soaking natural-silk-in-gum yarns.

Although the present invention will be particularly described in connection with its application to natural silk in gum yarns preparatory to textile processing of such yarns, either for throwing, weaving o'r knitting operations, it will be understood that the process and the product to be described herein'is also applicable with advantageous results to other types of yarn, such as rayon yarns.

Natural silk as it comes upon the market from Japan or other sources of supply usually consists of a plurality of strands of pure silk fiber, termed fibroin, which strands are more or less encased with a gummy material, termed sericin.

This sericin must eventually be removed since it gives the yarn, and fabric woven therefrom, a

rather harsh feel and a somewhat dull appearance, but it has been found most advantageous in the weaving and knitting processes to retain such gum or sericin upon the fibers for its bodygiving properties and to render the silk more readily handled in textile processing machinery.

However, this gum often tends to become tough and brittle, and when processed in textile? maweight organic compound or a soap may be usedto emulsify the otherwise immiscible oil, or the oil itself may be so sulphonated and combined with other sodium compounds as to be emulsifiable in itself.

However, it has been found particularly difficult to assure economic utilization of the oil in these baths and to assure effective absorption thereof by the natural silk in gum, since mere dipping of the skeins or immersion thereof was usually not satisfactory to assure a satisfactory absorption and in such case only such oil would be carried away by the silk fibers as would be contained in the liquid which would mechanically adhere thereto, most of which would afterwards be lost if the silk were subjected to a centrifugal extraction or whizzing operation.

To assure an effective absorption of the oil at- (Cl. 28 l) tempts have been made to coagulate the emulsion, as for example with a coagulating agent such as alum, and also attempts have been made to salt out the emulsion by adding a soluble alkali metal salt such as sodium chloride or sulphate, with resultant precipitation of the sodium salts of the sulphonated oils upon the fibers.

However, in case of either coagulation or salting out, as above described, the emulsion would be broken down so quickly as to give insufiicient time for absorption of the oil by the natural silk in gum fibers and with the result that the oil Would more or less form a smear or heavy greasy deposit upon the surface of the skein, which not only gives an undesirable unctious hand to the yarn, but in addition permits of removal of substantial quantities of the oil when the skeins were subsequently subjected to extraction.

0n the other hand, if too little of the coagulating or salting out agent is added, an unsatisfactory absorption is obtained and there is no way in which the absorption may be controlled by either a salting out process or a coagulating process, so that it would take place over a satisfactory length of time to enable most satisfactory penetration.

In my prior application, Serial No. 33,773 filed July 23, 1935, there is disclosed a utilization of ammonium and other salts of sulphuric acid, silicofluoric acid and other acids to assure satis factory discharge of the soaking bath and also to assure enhanced hygroscopic properties of the resulting silk, and it is among the objects of the present invention to provide other soaking processes to obtain the same result which will permit the natural silk in gum to be placed in a bath for any desired length of time, and preferably from eight hours to overnight with assurance, that a most effective and complete absorption of the oil from the soaking bath would be attained without forming a smear or unctious deposit on the surface of the yarn, and with further assurance that the absorption would be so complete that mere centrifugal extraction would not suflice to remove any substantial amounts of oil from yarns so prepared.

Another object is to provide a soaking bath for natural silk in gum and similar yarns which may be inexpensively made up and which may be most effectively utilized to assure most satisfactory absorption of the oil upon the silk yarns, and most effective use of the oilemployed.

Other objects will be in part obvious or will appear during the course of the following specification.

According to the present invention, it has been found most satisfactory to accomplish a gradual discharge of the disperse phase in the bath and also to secure a most satisfactory treatment of the natural silk in gum by the utilization of water soluble organic compounds containing a relatively high proportion of hydroxyl and carboxyl groups to the number ofcarbon atoms.

The most suitable compounds of this group which may be utilized for the exhaustion of the soaking bath and for a desirable disposition of the suspended or emulsified oily material upon the natural silk in gum or other fiber are the water soluble salts of aliphatic hydroxyl carboxylic acids.

The preferred acids are most desirably used in the form of their sodium salts, but potassium, ammonium or other alkali metal or alkaline metal salts may also be employed. It is most desirable that the compound contain at least two carbon atoms and preferably not more than about 20 to 24 carbon atoms.

Preferably, the ratio of the carboxyl and hydroxyl groups, combined, to the carbon atoms should be from 1:1 to 1:4 and in some instances up to 1:6 although these last mentioned compounds are usually not in the preferred range.

The ratio of carboxyl to hydroxyl may be 1:1 or vary on either side thereof so that there may be more hydroxyl than carboxyl or more carboxyl than hydroxyl.

As a general rule, however, it is desirable to increase'the number of hydroxyl groups in re lation to the carboxyl groups.

Although many different types of acids of the character described above may be employed, it has been found most satisfactory to utilize the sodium salts of alpha-lactic acid and less desirably beta-lactic acid.

In certain instances, other acids such as glycollic, glyceric, gluconic, fructonic, and so forth, may be employed in the form of their sodium salts.

In general, acids derived from the oxidation of polyhydric alcohols may be employed, and in some cases acids in which carboxyl groups have been replaced in part or whole by SOsH groups may be utilized.

In preparing the bath it has been found generally most satisfactory to utilize a sulphonated oil such as sulphonated olive oil, and. to neutralize this oil until its sulphonic or carboxylic acid groups and its sulphated groups have been in large part or wholly converted into sodium salts with sodium carbonate.

Itis to be understood that the present process is also applicable to other sulphonated or sulphated oils, such as menhaden oil, palm oil,

mustard seed oil, pea seed oil, cocoanut d. linseed oil, cottonseed oil, rape seed oil, castor oil, Neats foot oil, peanut oil, lard oil, tallow oil, elaine oil, corn oil, sperm oil, and/or fish oil and/or their fatty acids or mixtures thereof, and that other alkaline metal compounds may be utilized for neutralizing the sulphonated compound, as for example potassium carbonate and so forth.

As a general rule, the' discharging salt and the sulphonated oil material are added together to the soaking bath in such proportions and concentrations that the discharge will be substanmoved from the bath and caused to be absorbed by the yarns.

Preferably, the temperatures during this treatment in the soaking bath are maintained between to F. in the case of natural silks although the temperatures for other yarns such as rayon may be maintained between to F.

In general for every 100 parts by weight of natural silk in gum, 500 parts by weight of water are utilized in the soaking bath, and to the bath are added between 10 to 20 parts by weight of the sulphonated oil, between 1 to 3 parts by weight of potassium carbonate and between 1 to 2 parts by weight of discharging salt or discharging salt mixture.

For example, there may be employed about 100 pounds of raw silk and 60 gallons of water forming the soaking bath, to which are added about 16 pounds of a sulphonated oi1, 2 to 4 pounds of the lactate or other sodium carboxylate or mixtures thereof and 30 ounces of an alkalizing agent such as potassium carbonate, sodium carbonate or one of the sesquicarbonates.

To give several illustrative examples without restricting the invention thereto, for 100 pounds of natural silk in gum to be utilized in making knitting yarns for stockings, a bath is made up of 60 gallons or 500 pounds of water, in which is included 16 pounds of a sulphonated olive oil, 2 pounds of potassium carbonate and 1 pounds of the discharging carboxylate sodium salt mixture of the present application. V

For treating yarns to be utilized in making crepe silks on the other hand, 100 pounds of natural silk in the forms of skeins are immersed in 60 gallons or 500 pounds of water, including 12 pounds of sulphonated Neats foot oil, 2 pounds of sodium carbonate and 1 pounds of the salt mixture of the present application.

Suflicient sodium or potassium carbonate or other alkaline reagents should be added to neutralize the free fatty acids or other acids components and it is most desirable that at the end of the treatment in the soaking bath, which may befree from 10 hours to overnight, the bath does not change to acid condition. The treatment should end with the bath having a pH of about 7 or above.

Generally, in one hours treatment according to the present invention, it has been found that at least 25% of the oily material has been completely absorbed by the silk in gum, while with 8 hours and the above proportions, the absorption is substantially completed.

During this treatment with natural silk the temperature should be maintained between 70 to 100 F. although slightly higher temperatures may be utilized in the soaking of rayon.

In addition to the carboxylates, above mentioned, there may also be used ammonium salts such as ammonium chloride, ammonium sulphate,

ammonium silica-fluoride, ammonium acetate, ammonium phosphate, ammonium citrate, and also other alkali metal or soluble salts of these acids.

In addition, the ammonium may be replaced by various substituted ammoniums, containing methyl, ethyl, propyl, butyl, amyl or other. alkyl groups, which alkyl groups may be substituted by hydroxyl groups.

When the salt and the bath have been properly proportioned, it has been found that during the treatment, the pH will gradually drop oif from about 9 to 10 until it reaches about or is slightly ac'zaist above '7, at which time the reaction is substantially complete and all of the oil has been absorbed.

When the proportions have been selected as above stated, the silk which has been treated will have absorbed substantially all of the oil from the bath and it will be satisfactorily lubricated for textile processes, will not tend to become harsh or tough upon standing, but will readily pass through the reed, heddles, and shuttle eye and will not tend to generate any static charge.

In addition, the silk will be most satisfactory from a handling viewpoint of the silk throwster,

In the baths as above stated it is also possible that glycerine, glycols or other polyhydroxyl materials be employed.

In making the discharge bath, it is generally desirable that the bath initially have a pH of 9.8 to 10.

In combination with or in lieu of the above mixtures, the sulphonted oil itself may be finished or neutralized with ammonia to form an emulsifiable oil for addition to the bath. The disperse phase so formed may then be gradually discharged by the addition of an alkali, such as sodium or potassium carbonate.

The various aliphatic compounds above disclosed may also be substituted by other groups, such as aryl, aralkyl, nitro, sulpho, chloro, bromo, sulfhydroxy, amino, imino, amido, alkyl, alkylamino and so forth.

It is to be understood that many changes in the proportions, ingredients and treating conditions may be made without departing from the scope of the invention and it is intended to include all such alternative modifications and varia! tions as come within the scope of the appended claims.

The invention, however, is not intended to be restricted to any particular example, composition or proportions, or to any particular application, or to any specific manner of use, or to any of various details thereof, herein described, as the same may I be modified in various particulars or be applied in many varied relations without departing from the spirit and scope of the claimed invention, the practical-embodiments herein described merely showing some of the various features entering into the application of the invention.

In addition, to or in lieu of the sulphonated oils mentioned above, it is also possible to use sulphonated high fatty alcohols, such as lauryl, myristyl and oleyl alcohols, sulphonted naphtheine acids derived by treatment of white petroleum oil, and so forth.

Instead of the alkali metal and ammonium lactates or hydroxy carboxylates it is also possible to use alkali earth, earth metal or other metal salts where no undesirable precipitates are formed in the soaking bath.

Instead of the lactates and similar carboxylates, there may be used other compounds which break down to form aldehydes such as acetaldehyde which are readily oxidized to form acids. Possibly the rupture of the lactates to form acetaldehyde and sodium formate may be responsible to a greater or lesser degree for the action of the bath above described.

In some cases, lower aldehydes, as 40% of formalin, paraform, hexamethylene tetramine anhydroformaldehyde aniline, acetaldehyde, paraldehyde and other compounds readily oxidizable to form acidic materials may be added to the bath. If the bath is not already capable of oxidizing said aldehydes to form acids and thus gradually exhaust the bath, some non-precipitating oxidizing compounds may be used such as the organic peroxides, of the nature of benzoyl or stearyl peroxide hydrogen peroxide and so forth.

What is claimed is:

l. A process of soaking silk and rayon which comprises immersing said silk in a bath containing a soaking oil as a disperse phase and a discharging agent therefor including a water soluble carboxylated hydroxy aliphatic organic compound in the form of a water soluble salt.

2. A process of soaking silk and rayon which comprises immersing said .silk in a bath containing a soaking oil as a disperse phase and a discharging agent therefor including a water soluble hydroxlated aliphatic compound containing an acid group in the form of a water soluble salt.

3. A process of soaking silk and rayon which comprises immersing said silk in a bath containing a soaking oil as a disperse phase and a discharging agent therefor including a sodium hydroxy aliphatic carboxylate.

4. A process of soaking silk and rayon which comprises immersing said silk in a bath containing a soaking oil as a disperse phase and a discharging'agent therefor including an alkali metal salt of a hydroxylated aliphatic carboxylic acid.

5. A process of soaking silk and rayon which comprises immersing said silk in a bath containing a soaking oil as a disperse phase and a discharging agent therefor including an alkali metal lactate.

6. A process of soaking silk and rayon which comprises immersing said silk in a bath containing a soaking oil as a disperse phase and a discharging agent therefor including sodium alphalactate.

7. A process of soaking silk which comprises placing about pounds of natural silk in gum in the form of skeins in a soaking bath containing about 60 gallons of water, about 16 pounds of sulphonated olive oil, about 2 pounds of potassium carbonate, and about 2 to 4 pounds of a sodium lactate composition.

8. A process of soaking silk which comprises immersing about 100 pounds of silk in a bath containing about 60 pounds of water, about 12 pounds 9. A self discharging soaking bath for silk and rayon comprising a carboxylated hydroxy aliphatic organic compound, an alkaline metal carbonate a sulphonated oil and water.

10. A self discharging soaking bath for silk and rayon comprising a hydroxylated aliphatic acid compound in the form of a soluble salt, an alkaline metal carbonate, a sulphonated oil and water.

11. A self discharging soaking bath for silk and rayon comprising a sodium hydroxy-carboxylate, an alkaline metal carbonate, a sulphonated oil and water.

12. A self discharging soaking bath for silk and rayon comprising an alkali metal salt of a hydroxylated aliphatic carboxvlic acid, an alkaline metal carbonate, a sulphonated oil and water.

13. A self discharging soaking bath for silk and rayon comprising an alkali metal lactate, an alkaline metal carbonate, a sulphonated oil and water.

14. A self discharging soaking bath for silk and rayon comprising'sodium-alpha lactate,- an alkaline metal carbonate, a sulphonated oil and water.

15. A process of soaking silk which comprises placing natural silk in gum in the form of skeins in a soaking bath containing water, a sulphonated oil, an alkaline metal carbonate and an alkaline metal lactate, said materials being in the proportions of about 100 pounds of natural silk in gum, about 60 gallons of water, about 12 to 20 pounds of the sulphonated oil, about 0 to 6 pounds of the alkaline metal carbonate and about 2 to 6 pounds of the alkaline metal lactate.

16. A self discharging bath for soaking silk and rayon comprising water, a sulphonated 011. an

alkaline metal carbonate and an alkaline metal lactate in the proportions of about 60 gallons of water, about 12 to 20 pounds of sulphonated 011, about 0 to 6 pounds of the alkaline metal carbonate and about 2 to 6 pounds of the alkaline 5 metal lactate.

DALE S. CHAMBERLIN. 

